As someone who subscribes to those theories would you like to explain to me how one can be convinced of their existence without first accepting that they exist? Are you saying that believing in them affects the way light behaves coming into your eyes? In other words that my lack of belief in them makes light rays pass through them for ME, while for you it is reflected off them?
interesting questions, cursuswalker, and i would like to answer them.

firstly, my seeing fairies is not a result of subscribing to any theories about them, reality or perception. i see them and theorise later - and my seeing of them is not dependent on my coming up with a scientifically credible theory. either i see what doesn't exist, as in dreams when symbols manifest as visions, or what i see exists. just as my subjective assessment is employed in believing in my visible material surroundings, so my experiences of seeing ethereal beings are subjectively assessed, and it can't be otherwise until we develop tools for viewing what 'science' doesn't yet 'believe in' - the worlds beyond the veil - etheric and astral beings, for example. the fairy sight differs so much from dream-visions that it's unreasonable for me to believe they come about in anything like the same way. it's my belief that, as a function of a thinking planet, our culture leads little children to fairy rings and bestows the gift of second sight on the brave, hard-working few who are willing to work hard at becoming adepts of the fairy faith. trying to explain this is like trying to describe the colour blue to a colour-blind person. they have to believe what the majority describe, but when a minority describes what the majority can't sense, that's when you're up against it.
i'm not in a position to explain, only theorise about what is happening when i see them. i don't believe it's possible to explain how dream vision is made in the absence of light. some visions, eg of gnomes and some kinds of elves, occur only when i'm looking at them with eyes open - i catch sight of them among the plants while i'm gardening or harvesting garden produce. the same eyes that see the plants, also see fairies. others occur when i'm dozing as remotely viewed, and they too are not like dreams. there's an intense awareness of another mind or minds in contact with one's own that is quite absent from dream sequences.
as for how i could have 'etheric' vision, or 'the fairy sight', while you haven't, i can only say that during my life, sometimes i've had it, and sometimes i haven't. perhaps we open our eyes gradually in stages, seeing the material world first, then as our optics evolve, we begin to see also the astral world, the ethereal world and the other worlds of other substances in which we are embedded.
in obodry the gwersi refer to 'opening the psychic senses' - it's only a theory that 'psychic' 'senses' exist, and the idea is offered as a seed thought, but it reflects a commonly held belief - we have special senses developing which can be activated by meditation, auto-hypnotic suggestion and yeah, drinking clary sage tea, eating violets and semi-ripe mulberries and fully immersing ourselves in guided visualisations. when you study the range of responses to doing so, as i did for several years as a bardic and ovate tutor, you get convincing concensus.
i perceived fairies without seeing them, and talked to them constantly till i was eight, never tiring of the solitary fantasy, though the only reward for it came from them themselves. then i lost the rapport until i was about thirty. so the same pair of eyes sometimes can and sometimes can't. i then began to practice yoga, meditation and other techniques specifically designed to allow me to see the fairies that i knew were there on the edge of my perception. since most people with the fairie sight agree with me that it takes years of hard work to acquire and maintain it, of living apart from the hustle and bustle of towns, and maintaining good relations with all your neighbours, of eating and drinking moderately and loving nature, and perhaps it is necessary to have a tradition of it in the family, as i have on both sides.
if you want to understand more - hope this isn't mistaken for advertising - i wrote a book on this subject about ten years ago, with a foreword by philip carr-gomm. it's out of print now but you can download it for free as a pdf file here:
http://wyldwyverne.wordpress.com/2010/1 ... wild-moon/ or read it online here:
https://docs.google.com/leaf?id=0B-6fXq ... ZDYw&hl=en. if you visit my blog, there are several articles on the subject of seeing fairies. none of them deal scientifically with the physiology of second-sight. perhaps i should go into it more. to find them, click on 'the fairy dimensions' in my category cloud. not meaning to self-advertise

but it is on topic.
wyverne /|\